Spirulina Platensis Attenuates Rebound Dyspeptic Symptoms After Proton Pump Inhibitors' Discontinuation: Phase 2 Placebo-controlled Trial.

Context: Rebound acid hypersecretion after cessation of proton pump inhibitors (PPIs) can provoke dyspeptic symptoms. The search for alternatives to minimize the dyspeptic rebound symptoms after PPI discontinuation is warranted. Spirulina platensis, a dietary supplement made from blue-green algae, might be an alternative. Objective: The study intended to assess whether Spirulina platensis, through its anti-inflammatory and analgesic properties, can minimize rebound symptoms after PPI withdrawal. Design: The research team performed a randomized, phase 2, double-blinded, placebo-controlled clinical trial. Setting: The study took place at São Vicente de Paulo Hospital (trial registry number NCT04988347) in Passo Fundo, Brazil. Participants: Participants were 45 Brazilian patients in the clinical practice of two of the research team's member between November 2010 and February 2012, who were using PPIs regularly. Interventions: Participants underwent clinical and endoscopic evaluations after a 28-day run-in phase of 40 mg/day of pantoprazole. In the absence of a large hiatal hernia, peptic ulcer, or severe reflux esophagitis, participants stopped using PPIs, and the research team randomly assigned them to receive either 1.6g/day of spirulina or of a placebo for two months, followed by clinical and endoscopic reevaluations. Outcome measures: Using an intention-to-treat analysis, the primary outcomes postintervention were dyspepsia and typical reflux symptoms, either the appearance or maintenance of symptoms of >50% from baseline. Results: The median time of continuous PPI use was 32 months. The research team excluded two participants due to large hiatal hernias. Among the remaining 43 participants, 18 received spirulina (42%), and 25 used a placebo (58%). Two months later, 12 participants who had received spirulina (67%) and 18 who had received the placebo (72%) completed the study (P = .968). Rebound dyspepsia occurred in 10 out of 18 patients treated with spirulina (55.56%) and in 22 out of 25 patients treated with placebo (88%), with relative risk=0.63, CI95% (0.41-0.98), and P = .039. Reflux symptoms postintervention occurred in 72% and 76%, with the relative risk=0.95, CI95% (0.66-1.36), and P > .05, respectively. No significant side effects occurred in either group. The findings from endoscopy and gastric histology didn't differ between groups. Conclusions: A two-month course of Spirulina platensis was able to attenuate rebound dyspepsia but not reflux symptoms after PPI discontinuation. Considering its good safety profile, spirulina might be useful to relieve dyspeptic symptoms after PPI discontinuation.

Association between masticatory dysfunction and gastroesophageal reflux disease: A population-based study in the elderly.

BACKGROUND: Caries and periodontal disease may cause tooth losses and chewing difficulty, especially in the elderly. Ingesting poorly chewed food may delay gastric emptying and favour the development of gastroesophageal reflux disease (GERD). OBJECTIVE: This study investigated the association between masticatory dysfunction and GERD in the elderly from a rural area in southern Brazil. METHODS: This census invited all 489 elderly from a city to participate. The study used a GERD symptoms questionnaire, followed by an oral examination. Masticatory dysfunction was analysed based on the chewing difficulty for some food groups. Tooth loss and chewing self-perception were also considered as exposure variables. Poisson regression determined the association among variables by calculating the prevalence ratio [PR (95% confidence interval)]. RESULTS: The response rate was 93.1% (n = 455, average age of 70.9 years, 50.5% men). The prevalence of GERD in this population was 36.9%. GERD was associated with chewing difficulty for vegetables (PR = 1.54), meats (PR = 1.34) and cereals (PR = 1.43) but not with poor chewing self-perception (PR = 0.80) and tooth loss (PR = 1.22). GERD was also associated with xerostomia (PR = 1.63) and the female gender (PR = 1.35). CONCLUSION: Elderly people from a rural area with a reduced number of teeth present chewing difficulty and a high prevalence of GERD, indicating an association between GERD and masticatory dysfunction.

Disruption of the brain-esophagus axis in obese patients with heartburn.

Obesity is a risk factor for gastroesophageal reflux disease. Studies addressing the brain-esophagus axis in obese are lacking. In obese with and without heartburn, we assessed: (i) the brain responses to esophageal acid perfusion during functional brain imaging; (ii) esophageal impedance baseline before and after acid perfusion; and (iii) abdominal fat distribution. In this exploratory study, 26 obese underwent functional magnetic resonance imaging (fMRI) of the brain combined with esophageal acid perfusion. Esophageal impedance baseline was determined before and after fMRI, followed by tomographic quantification of the abdominal fat. Among 26 obese (54% men, 39.7 years old, 33.5 kg/m2), there were 17 with heartburn and 9 without heartburn. Before fMRI, the esophageal impedance baseline was lower in obese with heartburn than without heartburn (median 1187 vs. 1890 Ω; P = 0.025). After acid perfusion, impedance baseline decreased in obese with heartburn (from 1187 to 899 Ω; P = 0.011) and was lower in this group than in obese without heartburn (899 vs. 1614 Ω; P = 0.001). fMRI task-residual analysis showed that obese with heartburn presented higher functional connectivity in several brain regions than obese without heartburn. Abdominal fat area did not differ between obese with and without heartburn either for total (72.8 ± 4.4% vs. 70.3 ± 6.0%; P = 0.280), subcutaneous (42.2 ± 9.0% vs. 37.4 ± 9.0%; P = 0.226), or visceral (30.6 ± 7.9% vs. 33.0 ± 7.8%; P = 0.484). In subjects with obesity, the brain-esophagus axis is disrupted centrally with higher functional brain connectivity and peripherally with decreased esophageal mucosa integrity in the presence of heartburn.

Short-term intestinal effects of water intake in fibre supplementation in healthy, low-habitual fibre consumers: a phase 2 clinical trial.

A randomised clinical trial was conducted on 20 healthy, low-habitual fibre consumers to assess the short-term effects of water intake (2 l/day) on fibre supplementation with wheat bran, pectin, and green banana flour. During the 14-days trial, fibre intake doubled in both fibre (n = 10) and fibre/water (n = 10) interventions (p < 0.001), whereas daily water intake increased from 538 to 1990 ml in the fibre/water group (p < 0.001). Weekly bowel movements increased similarly in both interventions (fibre: 6.8-8.8; fibre/water: 8.6-10; p < 0.01), while faecal weight (71-126 g; p = 0.009) increased in the fibre/water group. This group showed higher counts of faecal Bacteroides and Prevotella, Faecalibacterium prausnitzii, and Bifidobacterium, whereas both interventions decreased the count of Desulfovibrio. Transient abdominal symptoms occurred less frequently in the fibre/water than in the fibre group (3 vs. 9 participants; p = 0.020). In healthy, low-habitual fibre consumers, short-term water intake helps the intestinal adaptation to fibre supplementation.CLINICAL TRIAL REGISTRATION NUMBER: NCT02838849.

Lactobacillus brevis CD2 attenuates traumatic oral lesions induced by fixed orthodontic appliance: A randomized phase 2 trial.

OBJECTIVE: To evaluate the effect of the probiotic Lactobacillus brevis CD2 on the prevention of early traumatic oral lesions induced by a fixed orthodontic appliance. SETTINGS AND SAMPLE POPULATION: Twenty orthodontic patients (14-57 yo) were recruited from a private clinic. SUBJECTS AND METHODS: In a phase 2, double-blind clinical trial, all patients were randomly allocated (1:1 ratio) to a 21-day course of soluble tablets containing L brevis CD2 (4 billion colony-forming units after breakfast, lunch and dinner) or placebo, starting at the day of orthodontic appliance placement. The primary outcomes were days with oral lesions and lesion-related pain [ranging between 0 (no pain) and 10 (maximum pain)]. Oral health-related quality of life was measured using OHIP-14 before and after treatments. RESULTS: All patients completed the study. Ten were treated with L brevis (28.1 ± 13.3 yo, 70% women), and 10 received placebo (27.5 ± 9.1 yo, 60% women). The oral lesions lasted significantly less time (P = .018) in patients treated with L brevis (2.5 ± 1.0 days) than with placebo (4.9 ± 3.0 days). Pain score was significantly lower (P = .039) when L brevis was used [median (min-max): 0 (0-4) vs. 3 (0-5)]. OHIP-14 scores were not significantly different between treatments. CONCLUSIONS: Lactobacillus brevis CD2 reduced almost 50% the persistence of traumatic oral lesions in patients with fixed orthodontics. Yet, there was no improvement in quality of life compared to placebo, suggesting that such differences in persistency and pain related to oral lesions may be considered clinically irrelevant.

Predictors of dental erosions in patients evaluated with upper digestive endoscopy: a cross-sectional study.

The most studied medical condition related with dental erosions is gastroesophageal reflux disease (GERD). The aim of this study was to assess other predictors of dental erosions besides GERD in outpatients referred for upper digestive endoscopy. In a cross-sectional study, we prospectively evaluated 235 patients who underwent upper digestive endoscopy. Patients were interviewed and examined by a trained dentist before the endoscopies, addressing dental health as well as clinical information and food intake. Dental erosion was classified using Basic Erosive Wear Examination score. Potential predictors for dental erosions were: gender, age, chronic use of antidepressants and proton pump inhibitors (PPI), diabetes mellitus, body mass index, heartburn and acid regurgitation scores, chocolate intake, reflux esophagitis and hiatal hernia. Overall prevalence of dental erosions was 23.4%. The most parsimonious Poisson regression model for dental erosions considered age, chocolate intake and acid regurgitation as predictors. Dental erosions were associated with acid regurgitation in patients younger than 50 years [adjusted prevalence ratio (PR) = 1.8 (95% CI 1.1-2.9)] and with chocolate intake in patients older than 50 years [PR = 2.1 (95% CI 1.2-3.9]. The surfaces most eroded were palatine/lingual (n = 25) and occlusal (n = 25), followed by vestibular (n = 5). In outpatients evaluated with upper digestive endoscopy, the variables associated with dental erosions were age younger than 50 years, acid regurgitation and chocolate intake. Referral for dental evaluation should be considered for young patients with GERD and frequent acid regurgitation.

How to select patients for antireflux surgery? The ICARUS guidelines (international consensus regarding preoperative examinations and clinical characteristics assessment to select adult patients for antireflux surgery).

OBJECTIVE: Antireflux surgery can be proposed in patients with GORD, especially when proton pump inhibitor (PPI) use leads to incomplete symptom improvement. However, to date, international consensus guidelines on the clinical criteria and additional technical examinations used in patient selection for antireflux surgery are lacking. We aimed at generating key recommendations in the selection of patients for antireflux surgery. DESIGN: We included 35 international experts (gastroenterologists, surgeons and physiologists) in a Delphi process and developed 37 statements that were revised by the Consensus Group, to start the Delphi process. Three voting rounds followed where each statement was presented with the evidence summary. The panel indicated the degree of agreement for the statement. When 80% of the Consensus Group agreed (A+/A) with a statement, this was defined as consensus. All votes were mutually anonymous. RESULTS: Patients with heartburn with a satisfactory response to PPIs, patients with a hiatal hernia (HH), patients with oesophagitis Los Angeles (LA) grade B or higher and patients with Barrett's oesophagus are good candidates for antireflux surgery. An endoscopy prior to antireflux surgery is mandatory and a barium swallow should be performed in patients with suspicion of a HH or short oesophagus. Oesophageal manometry is mandatory to rule out major motility disorders. Finally, oesophageal pH (±impedance) monitoring of PPI is mandatory to select patients for antireflux surgery, if endoscopy is negative for unequivocal reflux oesophagitis. CONCLUSION: With the ICARUS guidelines, we generated key recommendations for selection of patients for antireflux surgery.

Subacute stress and chronic stress interact to decrease intestinal barrier function in rats.

Psychological stress increases intestinal permeability, potentially leading to low-grade inflammation and symptoms in functional gastrointestinal disorders. We assessed the effect of subacute, chronic and combined stress on intestinal barrier function and mast cell density. Male Wistar rats were allocated to four experimental groups (n = 8/group): 1/sham; 2/subacute stress (isolation and limited movement for 24 h); 3/chronic crowding stress for 14 days and 4/combined subacute and chronic stress. Jejunum and colon were collected to measure: transepithelial electrical resistance (TEER; a measure of epithelial barrier function); gene expression of tight junction molecules; mast cell density. Plasma corticosterone concentration was increased in all three stress conditions versus sham, with highest concentrations in the combined stress condition. TEER in the jejunum was decreased in all stress conditions, but was significantly lower in the combined stress condition than in the other groups. TEER in the jejunum correlated negatively with corticosterone concentration. Increased expression of claudin 1, 5 and 8, occludin and zonula occludens 1 mRNAs was detected after subacute stress in the jejunum. In contrast, colonic TEER was decreased only after combined stress, and the expression of tight junction molecules was unaltered. Increased mast cell density was observed in the chronic and combined stress condition in the colon only. In conclusion, our data show that chronic stress sensitizes the gastrointestinal tract to the effects of subacute stress on intestinal barrier function; different underlying cellular and molecular alterations are indicated in the small intestine versus the colon.

Conventional Versus Traction-Assisted Endoscopic Submucosal Dissection for Esophageal, Gastric, and Colorectal Neoplasms: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Endoscopic submucosal dissection (ESD) is increasingly being utilized for the resection of superficial gastrointestinal neoplasms. However, the long procedure time poses a technical challenge for conventional ESD (C-ESD). Traction-assisted ESD (T-ESD) was developed to facilitate the procedure by reducing its duration. This study compares the efficacy and safety of C-ESD versus T-ESD in the treatment of esophageal, gastric, and colorectal neoplasms. Nine randomized controlled trials (RCTs) were analyzed. Traction-assisted ESD exhibited shorter mean dissection times for the esophagus and colorectal regions and lower perforation rates in colorectal cases. No significant differences were observed in en bloc resection or bleeding rates. Traction-assisted ESD proves to be more efficient in mean procedure time for esophageal and colorectal cases and safer in perforation rates for colorectal cases, but similar rates are noted for en bloc resection or bleeding.

Comfort, safety and quality of upper gastrointestinal endoscopy after 2 hours fasting: a randomized controlled trial.

BACKGROUND: Upper gastrointestinal endoscopy has been performed after fasting 8 or more hours, which can be harmful to the patients. We assessed comfort, safety and quality of endoscopy under moderate sedation after 2 hours fasting for clear liquids. METHODS: In this clinical trial, patients referred for elective endoscopy were randomly assigned to a fasting period of 8 hours (F8) or a shorter fasting (F2), in which 200 ml of clear liquids were ingested 2 hours before the procedure. Endoscopists blinded to patients fasting status carried out the endoscopies. Comfort was rated by the patients, whereas safety and quality were determined by the endoscopists. RESULTS: Ninety-eight patients were studied (aging 48.5 ± 16.5 years, 60% women): 50 patients (51%) in F2 and 48 in F8. Comfort was higher in F2 than F8 in regard to anxiety (8% vs. 25%; P = 0.029), general discomfort (18% vs. 42%; P = 0.010), hunger (44% vs. 67%; P = 0.024), and weakness (22% vs. 42%; P = 0.034). Regurgitation of gastric contents into the esophagus after endoscopic intubation did not differ between F2 and F8 (26% vs. 19%; P = 0.471). There was no case of pulmonary aspiration. Gastric mucosal visibility was normal in most patients either in F2 or F8 (96% vs. 98%; P = 0.999). CONCLUSIONS: Elective upper GI endoscopy after 2 hours fasting for clear liquids was more comfortable and equally safe compared to conventional fasting. This preparation might be cautiously applied for patients in regular clinical conditions referred for elective endoscopy. TRIAL REGISTRATION: SAMMPRIS ClinicalTrial.gov number, NCT01492296.

The brain-esophagus axis in subjects with and without obesity assessed by esophageal acid perfusion and functional brain imaging.

Background: Gastroesophageal reflux disease (GERD) has a complex pathophysiology and a heterogeneous symptom profile. The brain-esophageal axis in GERD has been studied with functional brain imaging during the last decades, but data from obese patients was just recently reported. A comparison of such a group with non-obese subjects is lacking in the literature. This study aimed to evaluate heartburn perception and brain connectivity responses during esophageal acid stimulation in subjects with and without obesity, controlling for the presence of typical reflux symptoms. Methods: In this cross-sectional study, 25 patients with obesity (body mass index ≥30 kg/m2) and 46 subjects without obesity underwent functional magnetic resonance imaging (fMRI) of the brain with esophageal water and acid perfusion. The fMRI paradigm and connectivity were assessed. Results: About two-thirds of the participants had reflux symptoms. Heartburn perception during fMRI did not differ between subjects with and without obesity. The presence of reflux symptoms was associated with lower activation in frontal brain regions during acid perfusion compared to water perfusion. Compared to subjects without obesity, patients with obesity presented significantly lower connectivity within the anterior salience network. Corrected clusters included left caudate, left putamen and left anterior cingulate gyrus. Conclusions: The brain-esophagus axis showed differences between subjects with and without obesity. Even without symptomatic differences following esophageal acid perfusion, patients with reflux symptoms showed less brain activation in frontal areas, while obese individuals presented lower connectivity within the anterior salience network.

Gastroesophageal reflux disease and dental erosion: The role of bile acids.

OBJECTIVES: To identify the bile acids in the saliva of patients with and without gastroesophageal reflux disease (GERD), and evaluate their effect on tooth surface. DESIGN: A cross-sectional study involved 26 GERD patients and 40 controls without GERD. Dental erosions were identified, saliva was collected and analyzed with chromatography for bile acid identification. An in vitro study assessed the effect of enamel exposition to taurocholic acid in concentrations of 1 µM, 10 µM, and a mixture of taurocholic acid and glycocholic acid at 10 µM on enamel microhardness, calcium release, and surface topography. RESULTS: Salivary bile acids were analyzed from 22 GERD patients and 40 controls. All these participants presented taurocholic acid and glycocholic acid in the saliva. The salivary amount of taurocholic acid was greater than glycocholic acid in both GERD patients (area under the curve: 7946 vs. 1361; p < 0.001) and controls (10,815 vs. 1290; p < 0.001). The salivary amount of taurocholic acid was greater in controls than in GERD patients (10,815 vs. 7946; p < 0.001). Dental erosion was more prevalent in GERD patients than in controls (27% vs. 7%; p = 0.041). In the GERD presence, the amount of glycocholic acid was greater in patients with dental erosion (1777 vs. 1239; p = 0.041). Enamel exposed to taurocholic acid at 10 µM, combined or not with glycocholic acid, had their microhardness increased, accompanied by calcium release, with no changes in surface topography. CONCLUSIONS: Taurocholic acid was the predominant salivary bile acid, particularly in controls without GERD. This bile acid had no deleterious effect on the enamel structure.

Reduced mastication is a risk factor for Rome IV postprandial distress syndrome in patients investigated with upper endoscopy.

BACKGROUND AND AIMS: Reduced mastication could force the stomach to do extra work on crushing food and contribute to dyspeptic symptoms. This study aimed to assess the relationship between mastication and dyspepsia. METHODS: This cross-sectional study involved 209 consecutive patients referred for elective upper endoscopy. Before endoscopy, an expert dentist performed an oral examination and scored chewing function in three levels (normal, regular, and reduced), and applied questionnaires for assessment of dyspepsia (Rome IV), xerostomia, and mastication (normal, regular, and reduced). A reduced masticatory function was defined when an oral examination or mastication questionnaire rated the chewing as poor. Associations between mastication, confounders, and dyspepsia were estimated by prevalence ratio [PR (95% Confidence Interval)] using Poisson regression. RESULTS: Thirty-four patients showed relevant organic conditions in the upper gastrointestinal tract (moderate to severe reflux oesophagitis, peptic ulcer, neoplasia, and surgical modification) and were excluded. Among 175 patients with non-organic diseases (aging 51.3 ± 15.7 years; 61.7% women), 50 (28.6%) had reduced mastication, and 125 (71.4%) had normal/regular mastication. After adjusting for age and xerostomia, reduced mastication was associated with postprandial distress syndrome [PR = 1.93 (95%CI 1.27 - 2.91)] but not with epigastric pain syndrome [PR = 1.09 (95%CI 0.75 - 1.60)]. CONCLUSIONS: In patients referred for upper digestive endoscopy, reduced mastication was associated with postprandial distress syndrome but not with epigastric pain syndrome. An interdisciplinary approach with dentists and physicians might benefit dyspeptic patients with postprandial distress syndrome.

Reduced masticatory function predicts gastroesophageal reflux disease and esophageal dysphagia in patients referred for upper endoscopy: A cross-sectional study.

BACKGROUND: The role of mastication on gastroesophageal reflux disease (GERD) is unknown. AIMS: To assess whether reduced masticatory function predicts GERD and esophageal dysphagia in patients investigated with upper endoscopy. METHODS: In this cross-sectional study, 179 adult patients referred for elective upper gastrointestinal endoscopy agreed to participate. Before endoscopy, an expert dentist performed an oral examination and scored chewing function in three levels (normal, regular, and reduced). Patients replied questionnaires for assessment of GERD (heartburn, regurgitation, and dysphagia), xerostomia, and mastication (normal, regular, and reduced). Poor chewing was defined when either oral examination or mastication questionnaire rated the chewing function as reduced. Associations of mastication with GERD and dysphagia were estimated using Poisson regression. RESULTS: Eleven patients were excluded. Among 168 analyzed (aging 49.8 ± 15.5 years; 58.9% women), 46 had reduced masticatory function (27.4%), and 122 had regular/normal mastication (72.6%). Reduced mastication was associated with GERD [PR = 1.38 (95%CI 1.12 - 1.70)], adjusting for age, and with esophageal dysphagia [PR = 2.03 (95%CI 1.02 - 4.04)], adjusting for age and xerostomia. CONCLUSIONS: In outpatients referred for upper gastrointestinal endoscopy, reduced masticatory function defined by an expert dentist may be a risk factor for GERD and esophageal dysphagia.

Obese patients have stronger peristalsis and increased acid exposure in the esophagus.

BACKGROUND: Obesity is a risk factor for GERD and a potential modulator of esophageal motility. AIM: To assess whether obese patients differ from non-obese patients in terms of esophageal motility and reflux. METHODS: Patients (n = 332) were categorized in GERD and controls after clinical assessment, esophageal manometry, and pH monitoring. Non-obese (BMI 16-29.9) and obese (BMI 30-68) were compared in regard of distal esophageal amplitude (DEA), LES pressure (LESP), manometric diagnosis, and esophageal acid exposure (EAE). RESULTS: Obese showed higher DEA in both controls (122 ± 53 vs. 97 ± 36 mmHg, p = 0.041) and GERD patients (109 ± 38 vs. 94 ± 46 mmHg, p < 0.001), higher LESP in GERD patients (20.5 ± 10.6 vs. 18.2 ± 10.6 mmHg, p = 0.049), higher frequency of nutcracker esophagus in controls (30 vs. 0%, p = 0.001), lower frequency of ineffective motility in GERD patients (6 vs. 20%, p = 0.001), and higher EAE in both controls [total EAE: 1.6% (0.7-5.1) vs. 0.9% (0.2-2.4), p = 0.027] and GERD patients [upright EAE: 6.5% (3.8-11.1) vs. 5.2% (1.5-10.6), p = 0.048]. Multiple linear regression showed that BMI was associated either with EAE (p < 0.001), DEA (p = 0.006), or LESP (in men, p = 0.007). CONCLUSIONS: Obese patients differed from non-obese in terms of esophageal motility and reflux, regardless of the presence of GERD. Obese patients showed stronger peristalsis and increased acid exposure in the esophagus.

Elimination of Angiostrongylus costaricensis larvae in feces from experimentally infected Swiss mice: circadian rhythm and correlation with survival.

Angiostrongylus costaricensis is a nematode which harbors mesentery arteries of rodents. In these animals, a circadian rhythm of elimination of first-stage larvae (L1) and a relation between the amount of L1 in feces and survival are unknown. We assessed fecal elimination of A. costaricensis L1 from experimentally infected Swiss mice and tried to correlate L1 elimination with survival. Thirteen Swiss mice were infected by gavage with ten A. costaricensis L3 larvae obtained from Phyllocaulis slugs. Feces were weighed at 7 A.M: . and 7 P.M: . starting from the 24th day post-infection until animal death. Feces sediment was examined in microscope for L1 counting. The mice were dead after a period ranging 19-61 days post-infection. Compared to diurnal samples, both feces' weight (2.3 ± 0.7 vs. 1.8 ± 0.5 g; P < 0.0001) and L1 total count [median 1,950 vs. 1,250; P = 0.015] were higher in feces eliminated at night. No difference was observed between diurnal and nocturnal elimination when counting L1 by gram of feces (725 vs. 650 L1/g; P = 0.821). A significant correlation was observed between survival and total number of L1 in feces (r = 0.84; P = 0.0007). This study suggests that mice experimentally infected with A. costaricensis eliminate more L1 at night due to higher fecal volume at this period. The correlation between number of L1 in feces and survival suggests a phenomenon of tolerance to A. costaricensis infection in mice with longer survival.

Outcomes in mice with abdominal angiostrongyliasis treated with enoxaparin.

Abdominal angiostrongyliasis (AA) is caused by the nematode Angiostrongylus costaricensis. Parasite-associated thrombosis of mesenteric vessels may lead to intestinal infarction, which might be prevented with anti-thrombotic agents. This study assessed the effect of enoxaparin on survival and pathological findings in Swiss mice with AA. In this experiment, 24 mice were infected with A. costaricensis (10 L3 per animal) followed by treatment with subcutaneous enoxaparin (40 mg/kg/day) or water (sham), starting from 15 days post-infection (dpi) and continued until animal death. Animals were monitored until death or sacrifice at the 50th dpi. Ten mice (42%) were dead after 36 ± 8 dpi. Of these, five (50%) were treated with enoxaparin. Animals treated with enoxaparin and sham did not differ in terms of weight loss (median, 1.3 vs. 4.2 g; P = 0.303) and macroscopical findings. Microscopically, no difference was found in regard to vascular granuloma (median grade, 2 vs. 3; P = 0.293) and presence of either vasculitis (75% vs. 100%; P = 0.217), mesenteric thrombosis (33% vs. 50%; P = 0.680), or bowel necrosis (25% vs. 50%; P = 0.400). Mice dead before the 50th dpi showed more pneumonia (90% vs. 21%; P = 0.002), bowel infarction (40% vs. 0%; P = 0.02), and purulent peritonitis (60% vs. 7%; P = 0.008) compared to survivors. Prophylactic enoxaparin in mice did not prevent tissue damage and mortality related with AA. The lower prevalence of mesenteric thrombosis and bowel infarction regardless of treatment were notorious. Frequent septic complications suggest the need of studies addressing the effect of antibiotics in AA.

Acid and weakly acidic solutions impair mucosal integrity of distal exposed and proximal non-exposed human oesophagus.

BACKGROUND: Oesophageal mucosa dilated intercellular spaces (DIS) may be important for symptom perception in non-erosive reflux disease (NERD). Patients with NERD might have DIS even in the proximal oesophagus. We aimed to assess the effect of oesophageal perfusions with acid and weakly acidic solutions on 'exposed' and 'non-exposed' oesophageal mucosa and its relationship to symptoms in healthy subjects. METHODS: 14 healthy volunteers underwent upper gastrointestinal endoscopy with biopsies at 3 and 13 cm proximal to the oesophagogastric junction (OGJ). In following sessions, subjects received 30 min perfusions with neutral, weakly acidic, acidic and acidic-bile acid solutions at 5 cm above the EGJ (separated 4 weeks). Biopsies were taken 20 min after perfusions. Electron microscopy was used to measure DIS. Subjects scored heartburn during perfusions using a visual analogue scale. RESULTS: (1) Oesophageal perfusion with acid solutions, with or without bile acids, provoked DIS in the 'exposed' oesophageal mucosa; (2) oesophageal perfusion with weakly acidic solutions provoked identical changes to those observed after perfusion with acid solutions; (3) distal oesophageal perfusions not only provoked changes in the 'exposed' but also in the more proximal 'non-exposed' mucosa; and (4) in spite of the presence of perfusion-induced DIS, most healthy subjects did not perceive heartburn during the experiments. CONCLUSIONS: The human oesophageal mucosa is very sensitive to continuous exposure with acidic and weakly acidic solutions. In spite of the presence of intraluminal acid and DIS, healthy subjects did not experience heartburn, suggesting that NERD patients should have other critical factors underlying their symptoms.

The impact of gastric bypass on gastroesophageal reflux disease in patients with morbid obesity: a prospective study based on the Montreal Consensus.

OBJECTIVES: To assess the impact of gastric bypass (GBP) on gastroesophageal reflux disease (GERD) based on Montreal Consensus. METHODS: In this study, 86 patients (25 men; aging 38 +/- 12 years; body mass index 45 [35-68 kg/m2]) were investigated for GERD before GBP and 6 months later. Esophageal and extraesophageal syndromes were assessed based on Montreal Consensus. Esophageal acid exposure and gastric pouch acidity were also evaluated. RESULTS: Overall prevalence of GERD was 64% before GBP and 33% after GBP (P < 0.0001). Typical reflux syndrome (TRS) was present in 47 patients (55%) preoperatively and disappeared in 39 of them (79%) post-GBP. Out of 39 patients with no symptoms, 4 (10%) developed TRS postoperatively (P < 0.0001). The chief TRS complaint changed from heartburn pre-GBP (96%) to regurgitation post-GBP (64%). Esophageal mucosa improved in 27, was unchanged in 51, and worsened in 8 patients (P = 0.001) in regard of esophagitis. Extraesophageal syndromes were present in 16 patients preoperatively and in none but one post-GBP (P = 0.0003). GERD-related well being and use of proton pump inhibitors were both improved after GBP. Total acid exposure decreased from a median (interquartile range, 25%-75%) of 5.1% (range, 2-8.2) to 1.1% (range, 0.2-4.8), P = 0.0002. Most patients (86%) showed and acid gastric pouch in fasting conditions post-GBP. CONCLUSIONS: GBP ameliorated GERD syndromes in most patients 6 months after the procedure, resulting in quality of life improvement and less proton pump inhibitors usage. Whether regurgitation post-GBP corresponds to reflux disease or bad eating behavior deserves further studies.